Gears get stuck in first

Hi, Everytime I stop the gears get stuck in first, unable to move out of first until moving again and then it is often difficult. Problem with gearbox, getting stuck in first gear, unable to get out unless the car is moving and then it can be difficult. Happening almost every time at traffic lights. Other gears seem fine. If I depress clutch and put in first I can move gears until the clutch is lifted and gear is engaged and then it gets stuck. Any advice much appreciated.